The core goal of the heavy-duty gas turbine manufacturing industry has always been to achieve efficient and precise manufacturing. The tenon groove machining of the heavy-duty gas turbine compressor disc and turbine turbine disc is a key quality control process in gas turbine manufacturing. The material used is high-temperature alloy, which has good mechanical properties, but the processing difficulty is high, and its processing quality directly affects the ability of the disc to withstand complex thermal alternating working loads.
We manufactured the first set of large-scale gas turbine disc groove cutters in China in 2010, which are used on large specialized CNC lathes. The entire set of cutters consists of 32 cutters with a total length of 21 meters, divided into coarse cutters, semi fine cutters, fine cutters, and correction cutters. This product was awarded the title of National Key New Product and the first domestic product (set) in the key field of equipment manufacturing in 2013, making it the first domestic product (set) in the key field of equipment manufacturing in Jiaxing City.
When designing the cutting tool, we fully consider the cutting deformation, reasonably distribute the structure of 32 knives, and design a unique correction knife structure to achieve progressive, efficient, and high-precision cutting of complex fir tree profiles; In the rough pulling stage, the use of one blade and multiple blades technology greatly reduces the total number of blades and shortens the total length of the blades; In the precision drawing stage, the same profile wheel cutting structure is adopted to achieve the same profile forming processing of the fir tree shaped wheel groove, reducing the cutting force of the wheel groove puller and improving the accuracy of the machined part tooth surface.
Application Case of Wheel Groove Puller
Precision and ultra large wire fir tree type gas turbine disc tenon groove processing
Wheel profile parameters:
Groove depth: 120mm
Slot width: 79.2 (0.2, 0) mm
Wheel thickness: 199.8mm, inclination angle 24 °
Actual cutting length: L199.8/cos24 °=218.7mm
Cutting parameters:
Cutting speed: coarse cutting blade 3m/min, fine cutting blade 1.5m/min
Tool parameters:
The entire set of knives consists of 43 knives, with a total length of 19.75 meters, including coarse knives, semi fine knives, fine knives, and correction knives.
Machine conditions: Imported CNC vertical lathe
Cooling method: oil cooling
Diagram of tool distribution:
Characteristics of Wheel Groove Pulling Knife
We have German imported CNC lathe grinding machines, which can process tool rake angle, rake angle, tooth lift, and online measurement; German imported CNC profile grinding machine can ensure the accuracy, stability, and service life of the cutting tool profile;
The horizontal projector detects cutting tools, ensuring high tooth profile accuracy and stable dimensions;
Final inspection, trial pulling of graphite blocks to further ensure that the tooth shape and size are qualified.
